Position Control of Traction Upper Limb Rehabilitation Robot Based on Fuzzy Sliding Mode Method

Given the shortcomings of traditional upper limb rehabilitation robots, such as large size and high price. A traction upper limb rehabilitation robot with omnidirectional wheels as a mobile platform is designed. In order to improve the control performance of the robot tracking training reference trajectory, reduce the chattering, and enhance the robustness, a variable reaching law parameter controller based on a fuzzy sliding mode control(FSMC) is designed in this paper. Reaching law parameters can be adjusted by fuzzy control(FC) and sliding mode reachability conditions which can reduce chattering and convergence time. First, the overall structure of the robot is presented. Then a kinematic model and an error kinematic model will be established. Next, sliding mode control(SMC) based on the error kinematic model is introduced, and the parameters of the power exponential reaching law(PERL) are adjusted by the fuzzy control strategy. Finally, the simulations and experiment demonstrate that the control method can effectively reduce chattering to enhance dynamic performance and stability.